KR20230084709A - Display device and mobile terminal including the same - Google Patents

Abstract

The present invention relates to a display device and a mobile terminal including the same, and relates to a first display panel including a first pixel array region and a light transmitting region, and a first display panel disposed under the first display panel and overlapping the light transmitting region. a second display panel including a 2-pixel array area; and disposed between the light transmitting area of the first display panel and the second pixel array area of the second display panel to allow light from the second pixel array area to pass through the light transmitting area through the light transmitting area. and a light guide module that refracts incident external light out of the second pixel array area.

Description

Display device and mobile terminal including the same {DISPLAY DEVICE AND MOBILE TERMINAL INCLUDING THE SAME}

The present invention relates to a display device and a mobile terminal including the same.

Electroluminescent display devices can be divided into inorganic light emitting display devices and organic light emitting display devices according to the material of the light emitting layer. An active matrix type organic light emitting display includes an organic light emitting diode (OLED) that emits light by itself, and has a fast response speed, high luminous efficiency, luminance, and viewing angle. There are advantages. Organic Light Emitting Diode (OLED) is formed in each pixel of the organic light emitting display device. The organic light emitting display device has a fast response speed, excellent luminous efficiency, luminance, viewing angle, etc., as well as black gradation. Since it can be expressed in complete black, the contrast ratio and color gamut are excellent.

Multimedia functions of mobile terminals are being improved. For example, a camera is basically built into a smart phone, and the resolution of the camera is increasing to the level of a conventional digital camera. The front-facing camera of a smart phone limits screen design, making screen design difficult. In order to reduce the space occupied by the camera, a screen design including a notch or punch hole has been adopted for smart phones, but the screen size is still limited due to the camera, so a full-screen display is required. could not be implemented.

In order to implement a full-screen display, pixels arranged with a low PPI (Pixels Per Inch) may be arranged in a pixel area overlapping a camera under the display panel. Light transmittance may be increased in the pixel area of low PPI, but blur may occur in an image captured by the camera due to pixels existing in the pixel area of low PPI, and thus the image quality of the captured image may deteriorate. Although such deterioration in picture quality can be improved with a picture quality compensation algorithm, the picture quality deterioration due to interference of pixels cannot be completely eliminated.

The present invention aims to address the aforementioned needs and/or problems.

The present invention provides a display device capable of realizing a full-screen display and improving the quality of an image captured by a camera, and a mobile terminal including the same.

The objects of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

A display device according to an exemplary embodiment of the present invention includes a first display panel including a first pixel array region and a light transmission region; a second display panel disposed below the first display panel and including a second pixel array region overlapping the light transmission region; and disposed between the light transmitting area of the first display panel and the second pixel array area of the second display panel to allow light from the second pixel array area to pass through the light transmitting area through the light transmitting area. and a light guide module that refracts incident external light out of the second pixel array area.

A display device according to another embodiment of the present invention includes a display panel including a first pixel array region, a light transmission region, and a second pixel array region; and a light guide module disposed below the light transmission area. A portion of the display panel where the second pixel array area is disposed is folded behind the light guide module so that the second pixel array area faces the light guide module. The light guide module includes a switchable liquid crystal lens including a liquid crystal layer disposed between the light transmission area and the second pixel array area to which an electric field is applied according to a liquid crystal driving voltage.

A mobile terminal according to an embodiment of the present invention includes a display panel including a first pixel array region, a light transmission region, and a second pixel array region; a light guide module disposed below the light transmission area; an optical sensor module including at least one optical sensor disposed at a position avoiding the light transmission area and into which external light refracted by the light guide module is incident; a display module that writes pixel data of an input image into the first and second pixel arrays; and a host system transmitting photo data received from the optical sensor module to the display module. The light guide module passes light from the second pixel array area toward the light transmission area and refracts the external light incident through the light transmission area toward the optical sensor module.

In the present invention, since an optical sensor module is disposed within a screen on which an image is displayed, a screen of a full-screen display can be realized.

The present invention can improve the quality of a captured image obtained from the optical sensor module because there are no pixels or circuit elements on the light path through which external light travels to the optical sensor module.

The present invention can minimize interference of external light incident on an optical sensor module when a user creates a self-photographed picture or a selfie image using a mobile terminal such as a smart phone, thereby improving selfie image quality.

The present invention can minimize noise in the output data of the optical sensor module when processing the user's biometric authentication, for example, the user's face authentication using data received from the optical sensor module, thereby preventing user authentication processing errors. there is.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a diagram showing a screen of a mobile terminal according to an embodiment of the present invention.
2 is a cross-sectional view schematically showing cross-sectional structures of a pixel array and a light transmission region of a display panel according to an exemplary embodiment of the present invention.
3 and 4 are cross-sectional views showing in detail a cross-sectional structure of a pixel array of a display panel according to various embodiments of the present invention.
5 is a block diagram showing the configuration of a driving unit of a mobile terminal according to an embodiment of the present invention.
6A and 6B are cross-sectional views showing structures of a display panel and a light guide module according to a first embodiment of the present invention in detail.
7 is a cross-sectional view showing in detail structures of a display panel and a light guide module according to a second embodiment of the present invention.
8 is a cross-sectional view showing in detail structures of a display panel and a light guide module according to a third embodiment of the present invention.
9 and 10 are diagrams showing structures of a display panel and a light guide module according to a fourth embodiment of the present invention in detail.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various forms different from each other, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, when the positional relationship of two parts is described as 'on ~', 'upon ~', '~ below', 'next to', etc., 'right' Or, unless 'directly' is used, one or more other parts may be located between the two parts.

In the description of the embodiment, first, second, etc. are used to describe various constituent elements, but these constituent elements are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Like reference numbers designate like elements throughout the specification.

Features of various embodiments can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or together in an association relationship.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1 and 2 , the screen of the mobile terminal 1000 is implemented by the display panels 100 and 300 of the display device. The display panels 100 and 300 include the first display panel 100 where most of the input image is displayed and exposed to the outside, and a portion of the input image displayed and disposed below the first display panel 100 to be exposed to the outside. and a second display panel 300 that does not become

The first display panel 100 and the second display panel 300 may be integrated or manufactured separately and physically separated. Each of the display panels 100 and 300 may be implemented as a flexible display panel in which pixels are disposed on a flexible substrate such as a plastic substrate, but is not limited thereto.

The pixel array regions PA1 and PA2 of the first and second display panels 100 and 300 include a plurality of data lines, gate lines crossing the data lines, and pixels connected to the data lines and the gate lines. include them Each of the pixels includes a light emitting element EL, a driving element driving the light emitting element EL, one or more switch elements, and a capacitor storing a gate-source voltage of the driving element. The pixel arrays PA1 and PA2 may be implemented as an active matrix pixel array in which each of the pixels includes a switch element. In another embodiment, the first pixel array area PA1 may be implemented as an active matrix pixel array, and the second pixel array area PA2 may be implemented as a passive matrix pixel array without a switch element.

The first display panel 100 includes a first pixel array area PA1 in which pixel data of an input image is written and a light transmission area UDC without pixels. The light transmission area UDC does not have the circuit layer 12 shown in FIGS. 3 and 4 . The light transmission area UDC may be disposed in the first pixel array area PAA.

The second display panel 300 includes a second pixel array area PA2 overlapping at least the light transmission area UDC of the first display panel 100 . The second pixel array area PA2 displays a part of the input image that cannot be reproduced in the light transmission area UDC of the first display panel 100, including pixels in which some pixel data of the input image is written. Accordingly, the input image may be reproduced as a combination of images displayed on the first pixel array area PA1 and the second pixel array area PA2.

There is no opaque material layer that does not block or interfere with light in the light transmission area UDC of the first display panel 100 . Accordingly, light emitted from the pixels of the second display panel 300 can propagate to the outside through the light penetrating area UDC, and light from the outside passes through the light penetrating area UDC to the first display panel. can propagate below (100).

The display device avoids the light transmission area UDC so as not to overlap the light guide module 200 disposed between the first display panel 100 and the second display panel 300 and the light transmission area UDC. It includes an optical sensor module 400.

The optical sensor module 400 may include one or more optical sensors, such as an imaging module (or camera) including an image sensor, an infrared sensor module, and an illuminance sensor module. The optical sensor module 400 may be disposed under the first display panel 100 at a position avoiding the light transmission area UDC, that is, not overlapping with the light transmission area UDC. The optical sensor module 400 does not overlap the second pixel array area PA2. The optical sensor module 400 may overlap the first pixel array area PA1, but is not limited thereto. The optical sensor module 400 may be disposed on substantially the same plane as the second display panel 300 .

The light guide module 200 is disposed between the light transmission area UDC of the first display panel 100 and the second pixel array area PA2 of the second display panel 300, and the second pixel array area PA2 ) passes through the light transmission area (UDC). On the other hand, the light guide module 200 refracts external light incident through the light transmission area UDC of the first display panel 100 out of the second pixel array area PAC. External light refracted by the light guide module 200 may travel to the optical sensor module 400 disposed while avoiding the light transmission area UDC. Therefore, external light may be incident to the optical sensor module 400 without interference because there are no pixels or wires connected to the pixels on the optical path of the external light directed to the optical sensor module 400 .

Light emitted from the second pixel array area PA2 passes through the light guide module 200 as it is and is propagated to the outside. When viewing the screen of the display device from the outside, the user can see a completely reproduced image with almost no difference in quality between the image reproduced on the first display panel 100 and the image reproduced on the second display panel 300 .

As shown in FIGS. 3 and 4 , the cross-sectional structure of the pixel array of the first display panel 100 includes a circuit layer 12, a light emitting element layer 14, and an encapsulation layer stacked on a substrate 10. ) (16).

The circuit layer 12 may include circuits necessary for driving pixels, such as pixel circuits connected to wires such as data lines, gate lines, and power lines. Wiring and circuit elements of the circuit layer 12 may include a plurality of insulating layers, two or more metal layers separated with an insulating layer interposed therebetween, and an active layer of a transistor including a semiconductor material.

The light emitting element layer 14 may include a light emitting element EL driven by a pixel circuit. The light emitting element EL may include a red (R) light emitting element, a green (G) light emitting element, and a blue (B) light emitting element. In another embodiment, the light emitting device layer 14 may include a white light emitting device and a color filter. The light emitting elements EL of the light emitting element layer 14 may be covered by a protective layer including an organic layer and a protective layer.

The encapsulation layer 16 covers the light emitting element layer 14 so as to seal the circuit layer 12 and the light emitting element layer 14 . The encapsulation layer 16 may have a multi-insulation layer structure in which organic layers PCL and inorganic layers PAS1 and PAS2 are alternately stacked. The inorganic films PAS1 and PAS2 block penetration of moisture or oxygen. The organic layer PCL flattens the surfaces of the inorganic layers PAS1 and PAS2. When the organic film (PCL) and the inorganic film (PAS1, PAS2) are stacked in several layers, the movement path of moisture or oxygen is longer than that of a single layer, effectively blocking the penetration of moisture and oxygen affecting the light emitting element layer 14. It can be.

A touch sensor layer 18 is formed on the encapsulation layer 16, and the polarizer 20 shown in FIG. 3 or the color filter layer 24 shown in FIG. 4 may be disposed thereon. The touch sensor layer 18 may include capacitive touch sensors that sense a touch input based on a change in capacitance before and after the touch input.

The touch sensor layer 18 may include metal wiring patterns 19 and insulating layers INS1 and INS2 forming capacitance of the touch sensors. The insulating layers INIS1 and INS2 may insulate a portion where the metal wiring patterns 19 intersect and planarize a surface of the touch sensor layer.

The polarizer 20 may improve visibility and contrast ratio by converting polarization of external light reflected by the metal of the touch sensor layer 18 and the circuit layer 12 . The polarizing plate 20 may be implemented as a polarizing plate in which a linear polarizing plate and a phase retardation film are bonded together, or a circular polarizing plate. A cover glass may be adhered on the polarizing plate. The linear polarizing plate can be interpreted as a half wave plate (HWP), and the circular polarizing plate can be interpreted as a quarter wave plate (QWP).

An adhesive 31 may be applied on the polarizer 20 and a cover glass 32 may be adhered thereon. The adhesive 31 may be an optically transparent adhesive (OCA).

The color filter layer 24 may include red, green, and blue color filters CF_R, CF_G, and CF_B. The color filter layer 24 may further include a black matrix pattern BM. The color filter layer 24 absorbs some of the wavelengths of light reflected from the circuit layer 120 and the touch sensor layer 18 to replace the role of the polarizer 20 and transmits the image reproduced in the first pixel array area PA1. Color purity can be increased. Therefore, the polarizer 20 is not required in the cross-sectional structure shown in FIG. 4 .

The color filter layer 24 may include an organic layer PAC covering the color filters CF_R, CF_G, and CF_B and the black matrix pattern BM and flattening the surface of the color filter layer 24 . A cover glass 32 may be adhered to the organic layer PAC of the color filter layer 24 .

The cross-sectional pixel array structure of the second display panel 300 may be implemented the same as or implemented with a different structure from that of the first display panel 100 . For example, at least one of the touch sensor layer 18 , the polarizer 20 , and the color filter layer 24 may be removed from the second display panel 300 .

5 is a block diagram showing the configuration of a driving unit of a mobile terminal according to an embodiment of the present invention.

Referring to FIG. 5 , the host system 50 of the mobile terminal may be connected to a power module, a sensor module, a communication module, a display module, and the like. The sensor module includes an optical sensor module 400 . The host system 50 may include an Application Processor (AP).

The host system 50 scales the input image according to the resolution of the first and second pixel array regions PA1 and PA2 of the display panel and transmits the scaled image to the display module.

The host system 50 may transmit photo data received from the imaging module of the optical sensor module 400 to the display module to reproduce a photo image on the screen. The host system 50 can adjust the brightness of an image reproduced on the screen by determining the brightness of the usage environment of the mobile terminal 100 based on data from the illuminance sensor of the optical sensor module 400 . The host system 50 may process the user's face authentication based on data received from the infrared sensor module of the optical sensor module 400 .

The display module includes the display controller 52 and the display panel driver 54 to write pixel data of an input image into the first and second pixel arrays PA1 and PA2 . The display controller 52 transmits pixel data of an input image received from the host system 50 to the display panel driver 54 .

The display panel driver 54 includes a data driver that converts pixel data received from the display controller 52 into a gamma compensation voltage and outputs a data voltage, and a gate driver that outputs a gate signal such as a scan pulse. The data voltage of the pixel data is supplied to the data lines of the pixel array regions PA1 and PA2. A gate signal is supplied to the gate lines of the pixel array regions PA1 and PA2. The display panel driver 54 may further include a touch sensor driver. The display controller 52 may include a timing controller that controls operation timing of the display panel driver 54 .

The host system 50 or the display controller 52 may control the lens driving unit 56 and the optical sensor driving unit 58 .

The lens driving unit 56 drives the switchable liquid crystal lens of the light guide module 200 under the control of the host system 50 or the display controller 52 to generate pixels of the second display panel 300. While passing the light emitted from the outside, it refracts external light toward the optical sensor module 400.

The optical sensor driver 58 drives each of the optical sensors of the optical sensor module 400 under the control of the host system 50 or the display controller 52 and transmits output data of the optical sensors to the host system 50. .

6A and 6B are cross-sectional views showing structures of a display panel and a light guide module according to a first embodiment of the present invention in detail.

Referring to FIGS. 6A and 6B , the first display panel 100 includes a first pixel array area PA1 , a linear polarizing plate 22 , and a first circular polarizing plate 21 .

The first pixel array area PA1 displays most of the input image including at least the circuit layer 12 , the light emitting device layer 14 , and the encapsulation layer 16 . In the light transmission area UDC of the first display panel 100 , a transparent portion 101 having no pixels and circuit elements is disposed. The transparent portion 101 is made of only a transparent insulating material, for example, an organic film and/or an inorganic film, in the circuit layer 12 and the light emitting element layer 14 .

The linear polarizer 22 and the first circular polarizer 21 may cover the display area where the first pixel array area PA1 is disposed and the light transmission area UDC. In the light transmission region UDC, the first circularly polarized light 21 may be disposed between the linear polarization plate 22 and the transparent part 101 . The linear polarizing plate 22 and the first circular polarizing plate 21 may be patterned to be disposed only in the light transmission area UDC. The linear polarizer 22 passes linearly polarized light traveling along a first optical axis, for example, a horizontal optical axis, from incident light. The linear polarization plate 22 may be a 1/2 wave plate (HWP). The first circular polarization plate 21 delays the phase of linearly polarized light by 45 degrees and converts it into circularly polarized light.

The second display panel 300 overlaps the first display panel 100 with the light guide module 200 therebetween. The second pixel array area PA2 overlaps the light transmission area UDC to display an image in the light transmission area UDC.

The light guide module 200 is disposed below the light transmission area UDC of the first display panel 100 . The light guide module 200 may include a switchable liquid crystal lens 220 and a second circularly polarizing plate 210 disposed between the switchable liquid crystal lens 220 and the first display panel 100 .

The first and second circular polarizers 21 and 210 overlap with the transparent portion 101 of the first display panel 100 interposed therebetween. The second circular polarization plate 210 delays the phase of the circularly polarized light incident from the first circular polarization plate 21 by 45 degrees and converts it into linearly polarized light traveling along a second optical axis, for example, a vertical optical axis. The second circularly polarizing plate 210 delays the phase of the linearly polarized light incident from the switchable liquid crystal lens 220 by 45 degrees and converts it into circularly polarized light.

The switchable liquid crystal lens 220 includes a first transparent electrode 221 formed on a first transparent substrate, a second transparent electrode 224 formed on a second transparent substrate, and a lens formed between the first transparent substrate and the second transparent substrate. 223 and a liquid crystal layer 222. An alignment layer may be formed on at least one of the first and second transparent substrates. In another embodiment, when the transparent electrodes 221 and 224 are patterned along a specific alignment direction, for example, when patterned in a stripe shape, the alignment layer may be omitted.

The first and second transparent electrodes 224 face each other with the liquid crystal layer 222 interposed therebetween to form an electric field in the liquid crystal layer 222 according to the liquid crystal driving voltage. The liquid crystal layer 222 can adjust the path of light by selectively refracting incident light using the refractive index anisotropy of liquid crystal molecules. The liquid crystal layer 222 may be implemented in a vertically aligned nematic liquid (VA) mode or other liquid crystal modes. The transparent electrodes 221 and 224 of the switchable liquid crystal lens 220 may be formed of ITO (Indium Tin Oxide), but are not limited thereto.

The lens 223 may be formed of an insulating material having an appropriate refractive index in an organic layer or an inorganic layer formed on the circuit layer 12 and the light emitting device layer 14 . The lens 223 refracts external light passing through the liquid crystal layer 222 due to a difference in refractive index with the liquid crystal layer 222 .

In FIGS. 6A and 6B , 'SW' denotes a switch element that applies a liquid crystal driving voltage in the lens driving unit 56 . In the display mode, the switch element SW is turned off, and in the optical sensor driving mode, the switch element SW is turned on so that an electric field can be formed in the liquid crystal layer 222 . The refractive index of the switchable liquid crystal lens 220 may vary according to the liquid crystal driving voltage. Accordingly, the focal length and image formation position (focal position) of the light refracted by the switchable liquid crystal lens 220 can be adjusted according to the liquid crystal driving voltage. In the optical sensor driving mode in which the switchable liquid crystal lens 220 is driven, the light refracted by the switchable liquid crystal lens 220 may travel to the lens of the optical sensor module 400 located avoiding the light transmission area UDC. there is.

When the switch element SW is turned off, there is no potential difference between the electrodes 221 and 224. At this time, the liquid crystal director of the liquid crystal layer 222 is in the horizontal direction.

When the switch element SW is turned on, a reference voltage is applied to one of the electrodes 221 and 224 and a liquid crystal driving voltage is applied to the other electrode. At this time, the liquid crystal molecules rotate due to the potential difference between the electrodes 221 and 224 so that the direction of the electric field between the electrodes 221 and 224 and the long axis direction of the liquid crystal molecules are aligned. At this time, the liquid crystal director of the liquid crystal layer 222 changes in the vertical direction.

The lens 223 may be formed of a transparent organic or inorganic material. The thickness of the lens 223 decreases as the distance from the optical sensor module 400 decreases, and a lens surface is formed on the surface thereof.

In display mode, no electric field is applied to the switchable liquid crystal lens 220 . In the display mode, there is no difference in refractive index between the liquid crystal layer 222 and the lens 223 . Therefore, as shown in FIG. 6A in the display mode, light from the pixels of the second pixel array area PA2 is transmitted through the switchable liquid crystal lens 220, the second circular polarizer 210, and the first display panel ( 100) and proceeds to the outside through the light transmission area UDC.

An electric field is applied to the switchable liquid crystal lens 220 in the optical sensor driving mode. In the optical sensor driving mode, the liquid crystal director of the liquid crystal layer 222 may change so that the refractive index of the liquid crystal layer 222 is greater than that of the lens 223 . In the optical sensor mode, as shown in FIG. 6B , after the linearly polarized light of the first optical axis passing through the linearly polarizing plate 22 passes through the first circularly polarizing plate 21 and is changed into circularly polarized light, the second circularly polarizing plate 210 After passing through, it is converted into linearly polarized light of the second optical axis and proceeds to the switchable liquid crystal lens 220 . External light incident on the switchable liquid crystal lens 220 proceeds to the optical sensor module 400 due to a difference in refractive index between the liquid crystal layer 222 and the lens 223 . An inverted image of an external object may be formed on the optical sensor module 400 . In the optical sensor driving mode, the optical sensor module 400 converts incident light into an electrical signal.

Circular polarizers 21 and 22 are disposed between the linear polarizer 22 and the switchable liquid crystal lens 220, but are not limited thereto. An n (n is a positive integer greater than or equal to 0) * λ/2 phase retardation layer may be disposed between the linear polarizer 22 and the switchable liquid crystal lens 220 . Here, λ is the wavelength of light. In the display mode, a circular polarizing plate (or λ /4 phase delay layer) may be disposed.

7 is a cross-sectional view showing in detail structures of a display panel and a light guide module according to a second embodiment of the present invention.

Referring to FIG. 7 , the first display panel 100 includes a first pixel array area PA1 in which a switchable liquid crystal lens 220 is embedded, a linear polarizing plate 23 and a circular polarizing plate 24 .

The first pixel array area PA1 displays most of the input image including at least the circuit layer 12 , the light emitting device layer 14 , and the encapsulation layer 16 . A switchable liquid crystal lens 220 without pixels is disposed in the light transmission area UDC of the first display panel 100 .

The linear polarizing plate 23 may cover the display area where the first pixel array area PA1 is disposed and the light transmission area UDC. The linear polarizer 23 passes linearly polarized light traveling along a second optical axis, for example, a vertical optical axis, from incident light. The phase retardation layer of the circular polarizing plate 24 is disposed on the linear polarizing plate 23 and the first pixel array area PA1. The circular polarizing plate 24 may be patterned so that only the transparent portion without the phase delay layer of the circular polarizing plate 24 exists in the light transmission area UDC. The switchable liquid crystal lens 222 may be overlapped with the linear polarization plate 33 with a transparent portion having no retardation layer interposed therebetween.

The second display panel 300 is disposed below the first display panel 100 and at least partially overlaps the first display panel 100 . The second pixel array area PA2 overlaps the light transmission area UDC to display an image in the light transmission area UDC. The switchable liquid crystal lens 220 is disposed in the light transmission area UDC on the same layer as the first pixel array area PA1.

In display mode, no electric field is applied to the switchable liquid crystal lens 220 . At this time, since there is no difference in refractive index between the liquid crystal layer of the switchable liquid crystal lens 220 and the lens, the light from the pixels of the second pixel array area PA2 passes through the light transmission area UDC of the first display panel 100. pass through and proceed to the outside.

In the optical sensor driving mode, an electric field is applied to the switchable liquid crystal lens 220 . At this time, due to the difference in refractive index between the liquid crystal layer of the switchable liquid crystal lens 220 and the lens, the linearly polarized light of the second optical axis passing through the linear polarizing plate 23 is refracted in the switchable liquid crystal lens 220 to form a light transmission area (UDC). It avoids and proceeds to the arranged optical sensor module 400 .

8 is a cross-sectional view showing in detail structures of a display panel and a light guide module according to a third embodiment of the present invention.

Referring to FIG. 8 , the first display panel 100 is disposed on the switchable liquid crystal lens 220 in the first pixel array area PA1 in which the switchable liquid crystal lens 220 is embedded and the light transmission area UDC. It includes a linear polarizing plate 25.

The first pixel array area PA1 displays most of the input image including at least the circuit layer 12 , the light emitting device layer 14 , and the encapsulation layer 16 . A switchable liquid crystal lens 220 without pixels is disposed in the light transmission area UDC of the first display panel 100 .

The phase retardation layer of the linear polarization plate 25 does not cover the first pixel array area PA1 and is disposed in the light transmission area UDC. Accordingly, the linear polarizing plate 25 may be patterned to be disposed only in the light transmission region UDC.

The second display panel 300 is disposed below the first display panel 100 and at least partially overlaps the first display panel 100 . The second pixel array area PA2 overlaps the light transmission area UDC to display an image in the light transmission area UDC. The switchable liquid crystal lens 220 is disposed in the light transmission area UDC on the same layer as the first pixel array area PA1.

In display mode, no electric field is applied to the switchable liquid crystal lens 220 . At this time, since there is no difference in refractive index between the liquid crystal layer of the switchable liquid crystal lens 220 and the lens, the light from the pixels of the second pixel array area PA2 passes through the light transmission area UDC of the first display panel 100. pass through and proceed to the outside.

In the optical sensor driving mode, an electric field is applied to the switchable liquid crystal lens 220 . At this time, due to the difference in refractive index between the liquid crystal layer of the switchable liquid crystal lens 220 and the lens, the linearly polarized light of the second optical axis passing through the linear polarizing plate 25 is refracted in the switchable liquid crystal lens 220 to form a light transmission area (UDC). It avoids and proceeds to the arranged optical sensor module 400 .

9 and 10 are diagrams showing structures of a display panel and a light guide module according to a fourth embodiment of the present invention in detail.

Referring to FIGS. 9 and 10 , the display panel 500 is manufactured to have a size larger than the screen of the mobile terminal 1000, and a portion of the display panel 500 is folded backward. The second pixel array area PA2 is disposed on the back-folded rear portion B of the display panel 500 .

A portion of the display panel 500 where the second pixel array area PA2 is disposed is folded behind the light guide module 200 so that the second pixel array area PA2 faces the light guide module 200 . Accordingly, the light guide module 200 and the second pixel array area PA2 overlap under the light penetrating area UDC without pixels in the display panel 500 .

The display panel 500 includes a front portion A on which the first pixel array area PA1 is disposed, and a rear portion B on which the second pixel array area PA2 overlapping the light transmitting area UDC is disposed. do.

The first and second pixel array regions PA1 and PA2 include a circuit layer 12 and a light emitting element layer 14 . The light transmission region UDC includes a transparent portion 101 made of only a transparent insulating material in the circuit layer 12 and the light emitting device layer 14 .

The first pixel array area PA1 disposed on the front portion A of the display panel 500 includes most of the input image including at least the circuit layer 12, the light emitting device layer 14, and the encapsulation layer 16. display An area C between the first pixel array area PA1 and the second pixel array area PA2 may be a blank area where no pixels are needed. Pixels may not be formed in this region C, but is not limited thereto. The second pixel array area PA2 disposed on the rear surface B of the display panel 500 overlaps the light transmission area UDC to display an image in the light transmission area UDC.

The light guide module 200 is disposed between the front part (A) and the rear part (B) of the display panel 500 . The switchable liquid crystal lens 220 of the light guide module 200 is embedded in the front part A of the display panel 500 as shown in FIGS. 7 and 8, or as shown in FIG. 9 the display panel ( 500) may be disposed in a space between the front part (A) and the rear part (B).

Since the display panel 500 is folded, if the pixels of the first pixel array area PA1 and the pixels of the second pixel array area PA2 are embodied with the same emission type, light may be directed in opposite directions. In consideration of this, pixels of the first pixel array area PA1 may be implemented as a top emission type, and pixels of the second pixel array area PA2 may be implemented as a bottom emission type. there is.

In order to increase the efficiency of light emitted from the pixels of the second pixel array area PA2, a reflective layer 502 reflects light incident from the pixels in the second pixel array area PA2 to the light transmission area UDC. can be formed. The reflective layer 502 may be formed of a metal having high reflectivity in the circuit layer 120 .

The optical sensor module 400 is disposed near the rear portion B of the display panel 500 avoiding the light transmission area UDC. The optical sensor module 400 may overlap the first pixel array area PA1, but is not limited thereto.

Since the content of the specification described in the problem to be solved, the problem solution, and the effect above does not specify the essential features of the claim, the scope of the claim is not limited by the matters described in the content of the specification.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and may be variously modified and implemented without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed according to the claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

50: host system 52: display control unit
54: display panel driving unit 56: lens driving unit
58: optical sensor driving unit 100, 300, 500: display panel
200: light guide module 400: optical sensor module
502: reflective layer 1000: mobile terminal
PA1: first pixel array area PA2: second pixel array area
UDC: light transmission area

Claims (19)

a first display panel including a first pixel array region and a light transmission region;
a second display panel disposed below the first display panel and including a second pixel array region overlapping the light transmission region; and
It is disposed between the light transmissive area of the first display panel and the second pixel array area of the second display panel to pass light from the second pixel array area to the light transmissive area, and is incident through the light transmissive area. and a light guide module that refracts external light to be outside the second pixel array area. According to claim 1,
The first pixel array region includes a circuit layer and a light emitting element layer,
The light transmitting region includes a transparent portion formed only of a transparent insulating material in the circuit layer and the light emitting element layer. According to claim 1,
and an optical sensor module disposed at a position avoiding the light transmission area to receive external light refracted by the light guide module. According to claim 3,
The display device wherein the optical sensor module is disposed on the same plane as the second display panel. According to claim 3,
The light guide module,
a switchable liquid crystal lens including a liquid crystal layer disposed between a light transmission area of the first display panel and a second pixel array area of the second display panel to which an electric field is applied according to a liquid crystal driving voltage;
The switchable liquid crystal lens,
first and second transparent electrodes facing each other with the liquid crystal layer interposed therebetween to form an electric field in the liquid crystal layer according to the liquid crystal driving voltage; and
A lens that refracts light passing through the liquid crystal layer;
A display device in which a difference in refractive index between the refractive index of the liquid crystal layer and the lens occurs when an electric field is applied to the liquid crystal layer. According to claim 5,
the lens,
A display device having a lens surface, the thickness of which decreases as the distance from the optical sensor module decreases. According to claim 5,
The first display panel,
A display device further comprising a linear polarizing plate and a first circular polarizing plate laminated on at least the light transmitting area. According to claim 7,
The light guide module,
Further comprising a second circular polarizing plate disposed between the switchable liquid crystal lens and the first circular polarizing plate,
A display device in which the first and second circular polarizers are overlapped with the transparent portion of the first display panel interposed therebetween. According to claim 2,
The light guide module,
A switchable liquid crystal lens including a liquid crystal layer disposed in a light transmission area of the first display panel to which an electric field is applied according to a liquid crystal driving voltage;
The switchable liquid crystal lens,
first and second transparent electrodes facing each other with the liquid crystal layer interposed therebetween to form an electric field in the liquid crystal layer according to the liquid crystal driving voltage; and
A lens that refracts light passing through the liquid crystal layer;
A display device in which a difference in refractive index between the refractive index of the liquid crystal layer and the lens occurs when an electric field is applied to the liquid crystal layer. According to claim 9,
the lens,
A display device having a lens surface, the thickness of which decreases as the distance from the optical sensor module decreases. According to claim 9,
The first display panel,
A display device further comprising a linear polarizing plate laminated on at least the light transmission area. According to claim 11,
The first display panel,
The display device wherein the switchable liquid crystal lens overlaps the linear polarizing plate with a transparent portion having no retardation layer interposed therebetween. a display panel including a first pixel array region, a light transmission region, and a second pixel array region; and
a light guide module disposed below the light transmission area;
A part of the display panel where the second pixel array area is disposed is folded behind the light guide module so that the second pixel array area faces the light guide module;
The light guide module,
A display device comprising a switchable liquid crystal lens including a liquid crystal layer disposed between the light transmission area and the second pixel array area to which an electric field is applied according to a liquid crystal driving voltage. According to claim 13,
The first and second pixel array regions include a circuit layer and a light emitting element layer,
The light transmitting region includes a transparent portion formed only of a transparent insulating material in the circuit layer and the light emitting element layer. According to claim 13,
and an optical sensor module disposed at a position avoiding the light transmission area to receive external light refracted by the light guide module. According to claim 15,
The switchable liquid crystal lens,
first and second transparent electrodes facing each other with the liquid crystal layer interposed therebetween to form an electric field in the liquid crystal layer according to the liquid crystal driving voltage; and
A lens that refracts light passing through the liquid crystal layer;
A display device in which a difference in refractive index between the refractive index of the liquid crystal layer and the lens occurs when an electric field is applied to the liquid crystal layer. a display panel including a first pixel array region, a light transmission region, and a second pixel array region;
a light guide module disposed below the light transmission area;
an optical sensor module including at least one optical sensor disposed at a position avoiding the light transmission area and into which external light refracted by the light guide module is incident;
a display module that writes pixel data of an input image into the first and second pixel arrays; and
A host system for transmitting photo data received from the optical sensor module to the display module;
The light guide module,
A mobile terminal configured to pass light from the second pixel array area toward the light transmission area and refract the external light incident through the light transmission area toward the optical sensor module. 18. The method of claim 17,
The light guide module,
A switchable liquid crystal lens including a liquid crystal layer disposed between the light transmission region and the second pixel array region to which an electric field is applied according to a liquid crystal driving voltage;
The switchable liquid crystal lens,
first and second transparent electrodes facing each other with the liquid crystal layer interposed therebetween to form an electric field in the liquid crystal layer according to the liquid crystal driving voltage; and
A lens that refracts light passing through the liquid crystal layer;
A mobile terminal in which a difference in refractive index between the refractive index of the liquid crystal layer and the lens occurs when an electric field is applied to the liquid crystal layer. 18. The method of claim 17,
The host system,
A mobile terminal for processing a user's face authentication based on the data received from the optical sensor module.

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